Retail vehicle washing services and the fabrication and sale of apparatus for performing vehicle washing and drying services have both become multi-million dollar businesses in the United States. One type of automatic car washer is the "tunnel washer" wherein a vehicle is rolled through a wash lane comprising a series of longitudinally spaced stations in which the vehicle is wetted, washed and rinsed. Many such car washers include a dryer at the terminal end where rinse water is removed by high velocity air, vehicle-contacting drying materials, and/or a combination of the two. For a more complete disclosure of an exemplary forced air dryer system, reference may be taken to copending application, "Vehicle Treatment Apparatus," Ser. No. 098,952, filed Sept. 2, 1987, and, assigned to the assignee of this application.
Frequently in this type of car washing apparatus, the machinery at the wetting, washing, rinsing and drying stations runs continuously even when no car is present in the wash lane, or it is started and stopped simultaneously for all stations when even a single customer-vehicle appears. These approaches are generally wasteful to energy, particularly the electricity which is consumed by high velocity blowers at the dryer station.